Composite wear-resisting body



Aug. 6, 1940. 1'. G. BEAMENT COMPOSITE WEAR-RESISTING BODY originalFiled Feb. 17, 195e offmserfi www@ MWMWMMWWWWWWZJ wmu SSN Patented Aug'.6, 1940 UN'ITED STATES PATENT OFFICE azionato ,25x-sagem 0..., 0....., A

original appunti February 11, 193s, serial No.

, 64,238. Divided 'and this application Septem- `1 bei' 27, 1937, SerialNo. 165,797

sired number of preformed, highly wear-resistant and suitably spacedinserts.

The invention resides in al new article of manu facture characterized bythe selection for the body member and inserts, respectively, of metals,alloys or classes of metal having physical properties which cause them;'when assembled` -in accordance with the invention, to enter into a newcooperative relationship productive of service, eiilciency and lastingqualitiessuperior to those ofl previously known composite wear-resistingobjects.

Another object of the present invention is to -provide a n'ovel articleof manufacture also char acterized by a novel distribution of areasbesultant capacity of heat transfer between thesel tween the inserts andthe body in which they are embedded, or a novel selection of the shapesand proportioning of the masses of the individual inserts to the mass ofthebody metal surrounding and spacing them apart so that-with theremembers of' the composite object in the original' casting of the bodyabout the inserts, the physical properties of said object'are superiorto those of known structure.

Still a further object of the present invention is to provide a novelarticle of manufacture embodying the principles of proper Aproportioningof the masses of the individual inserts to the mass of the body metalsurrounding and spacing the same apart to provide for theproper transferof heat between these members o'f the composite 'object in theoriginalcasting'A of the body about the inserts to secure the superior`physical properties hereinbefore mentioned, and which may be furthercharacterized ,by an. additional heat treatment consisting "ofsubjecting both of vthe metals, alloys or classes of metal,respectively', constituent ofi the inserts and the body, aftertheirassembly -and therefore simultaneously; which affects them differentlyand brings out in them those physical yproperties which enable them toenter into the novel cooperative relation aforesaid.

application is a divisionof mycopending application Serial No. 64.238,filed February 17,

1 )Other objects, features, capabilities and advantages are comprehededby the invention, as

will later appear and as are thereby.

Referring to the drawing:

Figure 1 is a plan view of an abrasion-resistant body produced inaccordance with the pres- 5 ent invention;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a section on the line 3-3 of Figvurei; and

Figure 4 is a chrono-thermographic -chart of temperatures developed inthe herein-described alloy inserts when submerged in moltenmangainheretly DOS-S8554. A

vnese steel poured into a mold in accordance with the present invention.16 I represents a composite body designed to serve as a crushing memberand rendered highly resistant to abrasion and of great structuralintegrity. by application of theA principles` oi the present invention.In said body, 2, 3, represent no inserts made of the herein-describedalloy having a high coeiliciency of resistance to abrasion.

' 'Ihese inserts are of two different designs, namely,

of circular and quadrilaterai section, respectively, alternated inpositions in a manner to render z5 substantially symmetrical theintervening embracing walls l of the body metal, which condition isenhanced by concaving thesides of the quadrilateral inserts.

As shown in Figures crease inA traverse dimension inwardly in order thatthey may be countersunk in the body i, and with the result that theintervening walls 4 increase in thickness outwardly, thereby materiallystrengtheningthe sustention of the ends of 35 the inserts where theymerge with the working surface of the body and at the Sametime, by thehighcontractile force, the separating walls 4 are given a large inwardmoment which, 'exverted upon the pyramidal vsides of the inserts,

" portion of the metal will vgenerally limit the the inserts to a rangecontaining presses the latter firmly to a seating upon that body whichunderlies the In producing objects under the present invention, thematerial of the wear-resistant in- 5 serts, 2, 3, is ofnsuch nature thatthe inserts can be best formed by casting. The' high degree ofwear-resistance Arequired of themand their essentially lower coeillcientof thermal contraction alloy or compositionpf atleast 1V2% v andpreferably 3% carbon; at least-1.50% and not greater than 10% 01 a metalof the chromium group, preferably 2% chromium: .with or withl outnickehthe nickel, if used, being in a proporu 2 and 3, inserts 2, :,mgo tionof at least 1% and not greaterthan 7%, and preferably 4%; and theremainder being es` sentially iron. Other constituents such asmanganese, silicon, sulphur, phosphorus and the like, ordinarily foundin castings, may be present in minor percentages without adding to ordetracting substantially from the quality ofthe a1-` loy employed forthe inserts; and these constituents when present may be regarded as'non-es,- sentials. The body memberi lwhich must not y only be tough andshock resistant but have a g'reatercoeiiicient of thermal contractionthan theinserts, is preferably made of iron with about 11i/2% carbon andabout 13% manganese, a1- though low carbon steel may be' used with ameasurableproportionof the advantages herein set forth. v

` An alloy falling within the ranges above outlined for the inserts doesnot possess its maximum potential resistance against wear if left in thecondition in which it is cast,.but requiresv a heat treatment comprisinga secondary heating ofthe said alloy to a temperature above its criticalpoint from which it may be cooled fairly rapidly. Surprisingly,treatment of the formed inserts, such, for instance, as-heating them to1850F. followed by quenching in water, somewhat softens the high carbonalloy i'romv which they are formed but renders it somewhat tougher thanit was in the condition as cast, and 'at the same time very materiallyincreases its' resist-y ance to wear. It has also been found that if.the inserts made of an alloysuch as above indicated be subjected to whatis commonly termed drawing, that is to say, reheatedto a relativelylowertemperature varying from 400 to 1200 F., or at least a temperature underthe critical tempera'- ture of the alloy.v for a period of from one tothreehours depending on the.drawing temperature, the hardnessisincreased materially andthe lresistance to wear is sometimes more thandou-- bled and even tripled, When an alloy of the above-describedcomposi-p tion, obviously too fragile to permit of its use-in producingthe body of an object subjected to shock or impact in use, is to besubdivided into the relatively small inserts or units such as indi'catedat 2, l, of Figures 1, 2 and 3` of the accompanying drawing, and theseunits. are-.to be nounted in a body member I made of thehereinidentified tough, ductile manganese steel, the hard, brittle,wear-resistant alloy is first cast-in the form of inserts; these insertsare then placed in a mold spaced one-from` another in a manner to insurebetween` them masses of body material. bearing a `desired relationshipto the mass ofthe inserts; the molten body material is then poured'under conditions that will insure its flowing around and lling thespaces between the inserts and therebyE developing heat'transfer of acapacity determined by the volumeof molten` metal in saidv spaces, andwhich said volume', by predetermination of said spaces, -is that -whichwill 'raise the temperatureof the inserts to a degree appropriate to thequenching in the heat treatment of the present invention before'thepoured metal hasY cooled below the temperature appropriateV toitsownquenching. Hence, when both components are subjected. to one andy'the,same quench, this quench will ail'ect the two-different alloysdifferently and'cause them'to enter into a new physical relationshipwhich will lend superior qualities to thennished object. The quench willY -preferably be that conventionallyused in the 'l5 productionof'o'bjects 'of manganesesteel. It will high compression, might rendervcomposite object. v

be from an appropriate degree of heat remaining after the cast, forinstance, about 1850 F., which temperature will have been imparted tothe inserts by the poured enveloping steel and will also beapproximately the temperature to which the s poured metal has cooledafter a few minutes of standing s The advantageous effect of thissimultaneous quenching from anappropriate heat of two dif- 'ferentmaterials herein identified as entering 10 into thel compositestructure, is that it bestows upon the respective materials physicalproperties that are quite distinct one from the other. It renders thebody-forming material tough and ductile at the same time 4that itrenders the inll serts hard and brittle; the brittleness, however,

' being counterbalanced by the embrace of the in- .serts'by the toughductile material, which embrace is of 'a higher order than in'previouslyknown cast composite objects. This heat treat- I ment lwill be stillmore effective if the lcomposite object receives -the further heatVtreatment of drawing from a temperature of 400i to 1200- say,V600-througli a period of from one to three hours. The quenching iseconomical because it u is from 'the casting heat and serves as well toproduce the quenching --indispensable to cast l manganese steel. Morethan this, quenching from the heatvsupplied by the casting operationconditions the enveloping body metal for contracting upon the insertsand firmly gripping them without developing checks'or cracks in thecooled casting; the high coefficient of thermal cdntraction in theembracing body metal, in cooling from its pouring heat and the highstresses of compression which vit imposes upon` the inserts rendersimpossible the loosening o! the inserts in the enveloping body, greatlyen" hances the sustention of ,the inserts against g spallingunder forcesencountered in use, all 40 makes it possible to use for the inserts analloy the brittlenesfs of whichfin the a'bnce of such l their use imypracticable.

By way oi' illustration of the advantage ofcon` 45 trolling heattransfer through the relative of the insert alloy and the,enveloplngbody alloy of the composite article, ,to-wit, by selecting theY spacingof properly shaped inserts inthe mold,

assume the introduction into a mold of one hun- I0 dredpounds of alloyinserts so spaced as to admit 'between and around them two hundredpounds ci molten steel at 3000 F., and that the mold be poured andpermitted to stand until the heat has become equanzed between the body'and vthe 1nsa serts, the meantemperature 4of the composite lmass willbe found -to stand at a point between '1800 and 1900 F. which may bejust-right-for` the -quenching *incident to the ilrst heat treatmentwhich the body and the inserts, jointly, are to l0 receive;A 'I'heproportion of body metal to insert H metal shouldbe such as, on the onehand, to prevent Aexcessive 'heating of the inserts-and, on

the other-hand, to insure sufficient heatingl as a preliminary to thequenching Btepin the heat A `treatment. In other words, the heattransfer from the molten metaljto the inserts should be s uch as toleave Aa final temperature above the critical for the' insert but below-the fusion temper'ature thereof. Subject to'these conditions, 70

the percentageof'insertmassmaybevariedbeltween 25% and 75% of the entiremass of the 'By way of further explanation. reference may y be had-tothe chartawearinscn the :company-f u' 'l impart to the insert alloy ingdrawing and consisting o f a time-temperature curve secured by insertinga thermo-couple in an insert while in position in the mold and thentaking the temperature readings at' periods commencing steel had beenpoured into the mold. This chart shows that the temperature was rapidlyraised to around 1700", then more slowly to 1850;v that it remainedabove 1700* for a period of around fteen minutes; and that this provedample t'o the qualities required before quenching in the rst heattreatment of the inserts.- y f o From the foregoing, it will be seenthat the present invention also contemplates the determining ofthemasses'of the insert and body metals entering into the compositestructure so that the ratio of the one mass to the other is such as willpermit utlizing the heat of the poured body such a unit will besubstantially superior to thatv apparatus subjected in use 1 ancewiththe present invention,

' l solid body,

metal for bringing the, initially cold inserts to a temperatureappropriate for quenching purposes andwithout cooling the poured metalto a temperature Vbelow ,that appropriate quenching; also, as corollaryto this, the .increasingor decreasing of the'percentageof body metal toinsert metal until the final temperature obtained in the mold isincreased or."decreased to the degree desired.

A simple and relatively inexpensive procedure within the broadest aspectof the invenll'fion,

. would be to make the inserts of a high-carbon,-

high chromium alloy which ls'not substantially Asoftened by heattreatment, then cast around these inserts a body mass of plain lowcarbon steel, then place the composite unit inservice withoutheatvtreatment. The performance' of of known structuresa plain mass ofmanganese steel, for instance'.

Among the particular fields of application to which the invention ishighly appropriate and which will serve to illustrate its. uses,v areore and other mineral grinding and crushing members, wearing plates for;ja'w crushers, wearing portions of crushing rolls, skid plates, chiitesand other to abrasive action of non-metallic materials. 1

In addition `to the very superior perfomance .characteristics'of anobject produced in accordfor instance, a rock'crushing member, theinvention also affords a number of production advantages. production ofcast manganese steel liner plates, for instance, the casting -yield isusually notover of -the nolten metal, due to the high shrlnk age ofheavy sections which must' be fed as a whereas with this insert` methodof l casting, especially when, as is preferred, thev sec'- vcls ,.Whenthe cost of melting ing and cutting" of the. mold 1o-invention becomes.quite evident.

tional areas of the inserts and of the interven-A ing body metal areabout equal, the chilling effect of'the'inserts and the `xliigfioding upof the body metal into thin'walls unding the inserts produces theequivalent of relatively thin chilled-cast plates or ceptable metalvbodies enveloping the new wear- 'resisting members'will usually be ashigh as 90%. e wastage and the like is considered, the saving affordedby the present Due to the cooling eiect of the inserts also, there is nofusmaterial as always occurs when these'units are cast in one piece;hence, cleaning costs aresubstantially re- I duced.

immediately after molten manganese to its own such as liners for ballmills or rod mills,

bars, and the yield of .ac-

heavy Another advantage of using inserts in manganese steel inaccordance with the presentinvention relates to their eect upon overallpattern shrinkage. Inthe production of some articles-.- rod millvliners, straight manganese steel is about lgthsl of an inch per foot,whereas in the insert construction the overall shrinkage is only aboutths of an inch perfoot.

In the making of heavy liner plates, jaw crushver parts, and the like,it is standard practice to employ dry sand molds, that is, molds ofvrelatively expensive composition, an additional cost in ovens untilthey are thoroughly dry and hard. With this insert practice,ordinary-green sand molds can be used with additional s'aving in timeand money. Furtherfor instance-shrinkage o f' which are baked at more,when any metal or alloy is made into castings'of large cross section andheavy .massive areas, there is quite a series and harmful segregationofconstituents, with large grain size and ,general interiormetallographic orientation of the metal which militat' against thehighest service. By filling the mold partly full of cold metal bodiesand then casting the body metal into thin chilled layers approximatingin thickv ness that of the inserts, the metal of the support- Sing bodybecomes very fine grained; tough in condition, and generally superior tothe same metal poured with heavy cross section.

Ixf these several applications of the invention, the inserts should bepractically surrounded on might presentY almost' any mosaic arrangementvof the insertl andl body metal, vitis desirable to stagger kthe confinesof the inserts, 'for' instance, by selecting designs such as illustratedon the drawing, toprevent continuity of planes of weakness. In thisconnection, it will be noted that the. designs of inserts are such thattheir masses are symmetrcally dstributed about their` centers ratherthan forming elongated polygons or vthe like.

The use of corrosion resistant alloy for the in? 'I have foundthat e t.serts has special advantages.

a large. portion of theI loss on wearing surfaces nordinarily ascribedtowear is dueto corrosion. Ordinary steels, for instance,- rust veryrapidly, and particularly when the surface film is in very unstable.condition due to' severe cold working of the surface itself, by the orebeing ground, or by grinding elements-balls, for instance. i-,During theactual operation of wet crushing, for example, the surfaces ofwear-resisting members l'rapidly rusted and progressively and repeatedlywipedof! by the abrasives, may, vbecause of their continued brightappearance, seem not to corrode, but the fact is that the losses throughcorrosion are large; Therefore, of twov metals havingthe same degree ofhardness or wearing resistance,` the one possessing the greatestresistance to corrosion will`lbestow longer operating life. Thevcomposite body of the present invention anords'. the advantage that thehigh 'carbon chromium `containing alloy has greater resistance toycorrosion than low carbon steeel or manganese steel, and for thisreason gives longer 4 life under conditions where progressive rust or'corrosion is a factor. r

vWhile I have herein described 'and upon the drawing shown anillustrative embodiment of the invention, it is to be understood thatthe invention is not limited 'thereto but may comprehend otherconstructions, arrangements of parts. details and features withoutdeparting from the spirit of the invention. `I claim: f-

1. A new article of manufacture, consisting of a composlte highlywear-resistant metal object comprising lnsertcomponents and a bodycoinponent in which the insert components are embedded, the bodycomponent being formed of an iron alloy containing about 1%% carbon and-/13% manganese, and the balance substantially all iron, and the insertcomponentsL comprising an alloy consisting of iron together with about3% carbon, 2% chromium and 4% nickel, and

said metal of said body component having a materially greater thermalcontraction than the metal of the' insert components.

2. A new article of manufacture, consisting of a composite, highlywear-resistant metaly object -con'iprising insert componentsiand a bodyconiponent.- in which the insert components are embedded,.the bodycomponent being formed of an iron alloy containing about'1%% carbon and13% manganese, ,and the balance substantially all iron, and the insertcomponents comprising an alloy consisting of iron, a metal of the chroniium group in a proportion of from 5% to 10%, nickel in a proportion offrom 1% to 7%, and carbon in a proportionv of from 1% to 3%, and iaidmetal oi'r said body component having a magreater thermal contractionthanthe metal4 of the insert components.

'moms asomar BFAMENT. zo

